Berlin 2015 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
MM: Fachverband Metall- und Materialphysik
MM 6: Functional Materials I: Battery Materials
MM 6.4: Vortrag
Montag, 16. März 2015, 11:00–11:15, TC 010
LiCoO2 and LiFePO4 thin-films for application in lithium ion batteries — •Martin Fiedler1, Antonia Reyes Jimenez2, Frank Berkemeier1, and Guido Schmitz3 — 1Universität Münster, Institut für Materialphysik, Wilhelm-Klemm-Str. 10, 48149 Münster — 2Universität Münster, MEET - Batterieforschungszentrum, Corrensstr. 46, 48149 Münster — 3Universität Stuttgart, Institut für Materialwissenschaft, Heisenbergstraße 3, 70569 Stuttgart
In commercial lithium ion batteries, powders of Lithium Cobalt Oxide (LCO) or Lithium Iron Phosphate (LFP) are commonly used as cathode materials. Contrary to this common approach, in this work LCO and LFP electrodes are prepared by magnetron sputtering, resulting in films of a thickness between 120 and 5500 nm. After deposition, the layers are characterized by X-ray diffraction, electron microscopy, and different electrochemical techniques. In particular, the influence of post annealing and in situ heating of the films in a temperature range between 400 and 700∘C is investigated, and it is found that the electrochemical performance of the layers significantly depends on both parameters. Moreover, it is demonstrated that, despite their large thickness, the cathodes are mechanically stable during cyclic lithiation/delithiation and thus allow detailed investigations of transport kinetics without being influenced by varying interface effects. In course of these measurements, the diffusion of lithium is investigated by means of electrochemical techniques, and is correlated to the microstructure of the layers. Finally, the technical relevance of the sputtered layers in functional full cells is presented.